Manual and electronic calendars are widely used. However, it is difficult to maintain synchrony between such calendars, some of which are annotated on paper, others of which are maintained online in computer calendar applications and mobile communication devices such as personal digital assistants (PDAs). This is particularly true in a family environment, for example, whereby a central family calendar is typically kept in one room, e.g. the kitchen, and marked-up and referred to by family members as they work out scheduling among themselves and while on the telephone. As such, there is difficulty maintaining synchrony of calendar entries between the central paper calendar and individual family members' electronic calendars maintained on, for example, their computers, PDAs, and mobile phone digital calendaring applications.
There are known solutions to the problem; however, none are particularly convenient for the typical user of both a traditional calendar and an electronic calendar. For example, one could use only electronic calendars. However, this approach does not address the practical reality of, for example, the home environment where more traditional, manual calendars are pervasive. One might also use purely passive paper calendars, and periodically synchronize with electronic calendars by a) hand-writing electronic calendar entries onto the paper calendar, or b) hand-entering paper calendar entries into electronic calendars. This approach is inconvenient and cumbersome to the users of both types of calendars. Moreover, it is subject to a high degree of human error and inconsistency.
In addition, another approach is to print calendars, such as a calendar 10 of FIG. 1, on paper printed with an address carpet, such as the Anoto dot pattern (described in connection with FIGS. 2(A) and 2(B)). When the calendar is marked with a suitable digital pen, such as an Anoto pen (generally described in connection with FIG. 3), the digital ink entries can be transferred to the corresponding dates and times on electronic calendars (not shown). This, of course, permits automatic or semi-automatic updating of electronic calendar entries from paper using, for example, digital ink recognition. However, hand-writing of electronic calendar entries onto the paper calendar is still required. This, too, is inconvenient and cumbersome, and is subject to a high degree of human error and inconsistency.
To further explain operation of a system of this type, with reference back to FIG. 2(A), address carpets allow digital tracking and recording of pen markings on physical paper. As shown, an array 20 of dots is configured in a grid pattern in a non-repeating manner so that each portion of the pattern has a unique dot pattern within its grid. This unique dot pattern provides an address for selected portions of the grid pattern. As is apparent from FIG. 2(B), the unique pattern is established by placing the dot in one of a plurality of positions relative to intersections of the grid. As shown, dot 22 is positioned to the right of the intersection. Dot 24 is positioned “up.” Dot 26 is positioned to the left of the intersection. And, dot 28 is positioned “down.” In this way, the Anoto dot pattern denotes two-dimensional location on a page by the displacement of dots from a regular grid.
A pen 30 is shown in FIG. 3. The components of the pen may vary and be configured in a variety of suitable manners within and about the pen 30, and is merely representatively shown for ease of reference. However, typically, the pen 30 includes a camera 32, a processor 34 and a memory 36. A battery 38 and wireless transceiver 40 are also housed within the pen 30. Of course, these items support the electronic nature of the pen. To accommodate the manual writing features of the pen 30, an ink cartridge and force sensor unit is provided. In operation, digital ink information can be obtained by the pen 30 through use of these components and then uploaded to a processor (not shown) for inclusion on an electric calendar via the wireless transceiver 40. Handwriting recognition software is, in many cases, able to perform character recognition to convert written text to ASCII symbols. In case handwriting recognition is unsuccessful or of low confidence, the raw digital ink can be transmitted and displayed. In any event, however, this system does not solve the problem of placing electronic calendar entries back onto a paper calendar.